Electric candy-warming table



'4 TToNEY April 14, 1925.

J. C. WOODSON ELECTRIC CANDY WARMING TABLE Filed D60. 2, 1922 11 T lllllll IIL AWM MM T www 7 1.1.41 w x 3 Q ,a

Patented Apr. 14, 1925.

` UNITED 'stares .Pari-:Nr OFFICE.

JAMES C. WOODSON, OF EAST PITTSBURGH, PENNSYLVANIA, ASSGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING- COMPANY, A CORPORATION OF PENNSYL- A VANIA.

, ELECTRIC CANDY-WARNING TABLE.

Application filed December 2, 1922. Serial No. 604,497.

To all whom t may concern.'

Be it known that l, Jar/Ins C. VVooDsoN, a citizen of the United States, and a resident of East. Pittsburgh, in the county of Allegheny and State of Pennsylvania., have invented a new and useful improvement in Electric Candy-Tanning Tables, of which the following is a specification.

My invention relates to electric'heating devices and particularly kto electrically heated candy warmers.

The object of my invention is to provide a relatively simple, rugged and electricallyheated surface of relatively large area that shall be uniformly heated. Y

In Vpracticing my invention, I provide a pair of superposed spaced sheet-metal plates having laterally extending and interengaging edge lianges. A plurality of layers of refractory heat-insulating material is l0- cated on the lower plate and supports a layer of a flexible electric-insulating material, to which is secured an electric heating element distributed substantially uniformly over the surface thereof. A layer of flexible electric-insulating material Vis located .above the heating element, and al layery of mica is located between the top metal plate and the superposed flexible layer of electric-insulating material. i

A removable cloth cover is located on the outside surface of the top metal plate, means being provided tov secure the side edges thereof to the down-turned edge flanges of 3 the top plate and further means being provided to clampthe end edge portions of the cloth cover against the edge flanges of the top plate. f

In the single sheet of drawings,

Figure 1 is a fragmentary top plan view of a device embodying my invention,

Fig. 2 is a view,V in vertical lateral section therethrough,

Fig. 3 is a partial longitudinal section therethrough, and y Fig. 4l is a diagrammatic representation of a heating element constituting a part of the device embodying` my invention.

A bottom sheet-metal plate 11, of substantially'rectangular contour, is provided, at each of-its-edges, with an integral upturned flange portion12. Upon the metal plate 11 is located alayer 13 of asbestos lumber. V1Upon the layer 13 is located a layer 14 of asbestospaper which is of relaedge strips 16, of L-shape in lateral section,

extending along/the side edges thereof. A

` plurality of flat-head machine screws 17 and co-operating nuts 18 serve to hold the members 16 against the edges of the superposed layers and also hold the threelayers in close operative engagement relatively to each other.

A heating element for the device comprises a plurality of helically wound resistor members 19 extending inV spaced relation longitudinally of the device. The individual resistor members arek secured against the layer 15 byy means of fine metal wire 21 at numerous points. A layer 22 of a heat-conducting and electric-insulating material, such as asbestos cloth, is located immediately above the resistor members 19 and has depending edge portions which eX- tend along the upturned edge fianges of the sheet-metal plate 11. A layer 23 ofmica is located immediately above the layer, 22

and is substantially a` co-extensive with the horizontal surface thereof. An upper sheetmetal plate 24 is located above the mica. plate 23 and has dependent integral edge flanged portions 25 which interengage with depending flanges of the upper asbestos cloth layerI 23. A plurality of sheet-metal screws 26 are employed to hold the upper sheet-metal plate in its proper operative position relative to the lower sheet-metal plate and extend through the two inter-engaging edge flanges of the plates, as well as through the depending edge-flange portions of the asbestos cloth 23. v

As hereinbefore stated, a plurality of substantially parallel-extending helices are provided, one e-nd of each of which is connected to a common bus bar 27 located adjacent to one end of the device. At the other end of the device and within the casing formed by the two sheet-metal plates, are provided three bus bars28, 29 and 31,V to which thel other lends of the' respective individual helices of Wire are alternately connected.

It is thus possible to selectively connect port-ions oi the entire heating element, comprising the pluralitvr oit helices through controlling device, such as switches, (not shown), to a suitable source of electric ener y in Vorder to vary the amount ot energy ated in the' wire, while still maintaintransl ing a substantially uniform distribution ol heat -from the surface of the device during the operation thereof.

The bus bars 28, 29 and 31 are secured in their proper operative positions by means ot bolt-s 3Q, a plurality ol nuts 33 being provided on each bolt to permit ot securely clamping the bus bar in its proper operative position, as well as permitting the connection to the bolt ot the ends ot suitable supply-circuit conductors, not shown. iin insulated wire 34 may be connected to one end of the bus bar 2? and to a common terminal member 35 located adjacent to the terminal bolts 32. A terminal box` 3G may be employed to suitably protect the exposed terminal members, as hereinbet'ore described, and be mounted upon 'the underside 0i' the lower sheet-metal plate.

During the operation of the device which is usually employed to maintain candy at al predetermined temperature during the course of manufacture, the outer surface oil' the upper sheet-metal plate is covered by a canvas cloth 37.

The cloth 57 is made large enough to provide integral edge-flange port-ions 38, the side flanges being provided with a plurality of metal eyelets 39 adapted to operatively engage studs il which are suitably secured against thc side flange portions 25 of the metal plate 24, the object being to maintain the cloth tightly stretched. ln order to further assist in drawing the cloth cover 37 tightly over the surface ot the upper sheet-metal plate, additional stretching and clamping means are provided and coniprise metal bars 4:2, et substantially U-sliape, the inner ends oi' which are pivotally seeml d against the flanges 25 by rivet members i3 adjacent to the ends or" the device. rlhe construction is such that the member 4t2 may be raised to a substantially vertical position, the cloth stretched adjacent to the ends as much as possible. atter which the clamping member is moved to its normal operative position, whereby the cloth cover is stretched and then tightly clamped against the end portion of the metal plate.

As this device is intended to be mounted ina substantially7 horizontal position, a plurality of angle bars le are secured against the under surface of the lower sheet-metal plate, the distance therebetween being in accordance with the width of the table upon which the device is to rest. Y

The device embodying my invention thus provides a casing comprising` two spaced sheet-metal plates having interengaging `flange portions7 a plurality oft layers of heatinsulating and electric-insulating material loca-ted therein, and a plurality oi substantially uniformly distributed resistor members, a plurality o' layers ot electricinsulating material being employed to insulate the heating element trom the top sheet-metal plate. li removable cloth cover is provided with means for permitting it to be tightly stretched over the upper sheet-metal plate from which it may be easily and quickly removed whenever required.

Various modiiications and changes in detail and arrangement may be made. without departing trom the spirit and scope oi the invention, and such moditications are intended to be covered by the appended claims.

l claim as my invention:

l. ln an electrical heating device., in combination, a sheet-metal plate having upturned edgeiianges, a. layer oit heat-insulating material on said plate, a layer of iiexible electrical-insulating material on said heatinsulating material, a resistor member located on and secured to said layer oit electrical-insulating material, a layer of electrical-insulating material over said resistor and a superposed sheet-metal plate having downturned edge flanges operatively engaging the upturned edge iianges of said first sheet-metal plate.

2. In an electrical heating device, in combination, a casing comprising a pair of spaced coextensive sheet-metal plates having laterally extending edge Aflanges operatively engaging each other, a layer ot heatinsulating material on one of said pla-tes, a heating element located thereon, a. layer of flexible refractory electric-insulating material between said heating element and the other ot said plates, and means operatively engaging said edge flanges tor holding said layer oi heat-insulating material against said plate and :tor holding said plates in proper' operative positions relatively to each other.

3. ln an electrical heating device, in coinbination, a sheet-metal plate, a plurality of layers ot electric-insulating and heat-insulatino; material located on said plate, a layer ot flexible refractory electric-insulating mate ial on said layers of insulatingr material, means for securing said layer of Yflexible material against said layers 0i insulating material and a helically-wound resistor wire secured to said Vflexible material.

il. ln an electrical heating device, in combination, an upper and a lower sheet-metal plate having intcrengaging edge flanges, a layer oi a heat-insulating material on said lower plate, a layer oit electric-insulating material on said heat-insulating material, a heating element secured to said electric-insulating material, a layer of electric-insulating material between said upper sheet and said heating element, and a cloth cover member removably associated with said upper sheet-metal plate.

5. In an electrical heating device, in combination, an upper anda lower sheet metal plate having interengaging edge flanges, a layer of a heat-insulating material on said lower plate, a layer of electric-insulating material on said heat-insulating material, a heating element secured to said electricinsulating material, a layer of electric-insulating material between said upper sheet.

and said heating element, a cloth cover member removably associated with said upper sheet metal plate and means for securing the side edges of said cover member to said upper sheet metal plate.

6. In an electrical heating device, in com-v bination, an upper and a lower sheet metal plate having interengaging edge flanges, a layer of a heat-insulating material on said l lower plate, a layer of electric-insulating maedges of said cover member to said upper sheet metal plate, and means for stretching the end portions of said cover member and for holding them tightly against the end flanges of said upper plate.

In testimony whereof, I have hereunto subscribed my name this 27th day of N0- vember, 1922.

JAMES C. WOODSON. 

